<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <h1>123</h1>
    <a>234</a>
    <div class="box">345</div>
    <p id="aaa">456</p>
    <script src="./jquery-3.6.0.js"></script>
    <script>
        let a = $("h1")
        console.log(a);
        let b = $("a")
        console.log(b);
        let c = $(".box")
        console.log(c);
        let d = $("#aaa")
        console.log(d);
        $("h1").css("fontSize", "12px")
        $(".box").css("backgroundColor", "red")
        $("a").css("color", "blue")
        $("#aaa").css("margin", "100px")
    </script>
</body>

</html>